Method of garbage reduction



R. D. MaGLAURlN ET AL METHOD OF GARBAGE REDUCTION May 3, 1927. 53

Filed March 5. 1926 [:1 [:1 (:)\/l E f: (IZZY I. 'ENTORS .-1 T'I'ORNE W.

Patented May 3, 1927.

" UNITED STATES rArsurorrlcs."

Elli

ROBERT D. MAGLAURIN, OF LAKEWOOD, AND CHARLES C. SMITH, OF CLEV ELAND, OHIO.

- METHOD or GARBAGE REDUCTION.

The present invention relates to garbage reduction and more particularly to a process bage is dehydrated without burning or charring and after being completely dehydrated has the grease and fats removed and the remainder is handled to produce the usual tankage or fertilizer. To the accomplishment of the foregoing and related ends, said.

invention, then, consists of the steps hereinafter fully described and particularly point ed out in the claims.

The annexed drawing and the following description set forth in detailone approved method of carrying out the invention, such disclosed mode, however, constituting but one of the various ways in which the principle of the invention may. be used.

In said annexed drawing The single figure there appearing is a diagrammatic layout of a plant embodying the present method. F v

' The present reduction process, as shown by the drawing which diagrammatically shows a complete plant layout, provides a direct heat dehydrator 3 into which the gar-- bage is first carried from a storage tank 1, thearbage first passing through a rotary filter 2, which removes the free water from the green garbage. In the direct heat dehydrator, which is preferably of the rotating cylinder type, the green garbage is dehy drated from its normal moisture content of about 7 2 per cent to about per cent. Such preliminary dehydration can ordinarilyv be effected by a direct heat dehydrator without causing any nuisance, but should noxious gas be produced, these are readily burned by passing them throughthe rubbish incinerator unit 4, this unit being also adaptable for the production of steam for the other steps in the process. I

When the green garbage-has been dehynpplication filed March 3, 1926. Serial 'No. 919Gb.

drated to about 35 per cent of moisture, it is passed into a separating and disintegrating unit 5, in which it is first hand sorted to remove foreign matter, and then passed over a magnetic separator for the removal of iron and steel such as cans and the like, and is then disintegrated or reduced to a fairly fin'e condition ready for "further treatment.

From this unit the disintegrated material is passed into a steam tube drier 6 for fur ther dehydration and here the moisture con tentis reduced to about 10 per cent which is the normally dry point of the garbage. This dehydration in steam tube driers eliminates the production of noxious gases and also prevents the carbonization or burning'ot the material. This further dehydration from 35 per cent to about 10 per cent of moisture is rapidly carried out in the steam tube .driers rovided that the material has been,

proper y disintegrated and the prevention of charring or partially burning or the garas to the grease tocbe extracted and the leftover tankage or fertilizer.

From the steam tube driers, the dried ga'rbage is charged into the extractor which may be of any suitable type, thatillustrated being a suitable percolator and the extrac tion material such as naphtha is added, and

the grease and fats are removed, steam being used for the evaporation of the solvent. In the plant illustrated, there are shown the stills 8, condensers 9;, grease storage tanks 10,

and solvent storage tanks 11.

After the grease is extracted, the tankage is passed into a second steam tube drier 12, which removes the moisture'taken up from the steam used in evaporating the solvent and then the material is passed into a grinder By the present process, the economy bage conserves the value of the garbage both as the steam tube driers are substantially as eflicient forthe final dehydration as a direct integrated after the heat drier when the material is properly dispreliminary dehydration. I

The loss of solvent 0r grease extraction material is kept at a minimum as no solvent is added to the garbage until final drying has been accomplished and thus the extraction is carried out as a separate step. By preventing burning or ca'rbonization of the material, the value of the tankage and the grease is maintained at its highest point. If at any time noxious odors are produced in the direct heat dehydrator, these are easily prevented from becoming a nuisance by being burned in the rubbish incinerator which is also used to produce steam for the steam used after preliminary drying, the larger losses of solvents occur during the "further reduction and removal of Water. In the present method, the second dehydration is accomplished Without danger of burning and as no solvent is present, there are no losses during this step of the procrss.

This process also eliminates the fire hazard Which is present Where fire driers are em ployed to dehydrate from thirty-five per cent (35) to ten per cent (10) moisture as at low moisture content, the liability of fire and explosion is serious. Similarly, the fire hazard is present in reducers as the solvent such as naphtha is an explosive and when the reducers are opened for testing of material, combustible gases are expelled in large quantities.

The entire apparatus can be conveniently grouped so as to economically handle and move the garbage through the several units and the cost of the units themselves is comparatively loW as standardtypes of driers, extractors, etc. may be employed. Powdered fuel canadvantageously be employed in the direct heat dehydrator and the incinerator stack 21 used for the gases produced as well as for the incinerator gases themselves.

Other modes of applying the principle of our invention may be employed instead of the one explained, change being made as regards the process herein disclosed, provided the step or steps stated by any of the following claims or the equivalent of such stated step or steps be employed.

We therefore particularly point out and distinctly claim as our invention 1- 1. In a garbage reduction process, the steps of preliminary dehydration of the green garbage through the non-critical moisture zone by direct heat, then further dehydration through the critical moisture zone by indirect heat, extraction of fats, and. the

redrying ofthe tankage by indirect heat.

2. In a garbage reduction process, the steps of preliminary dehydration of the green garbage through the non-critical moi sture zone-by direct heat, distintegration of preliminary dried garbage, further dehydration through the critical moisture zone by indirect heat, extraction of fats, and redryiug of the resultant tanlrage by indirect heat.

In a garbage reduction process, the

5. In a garbagereduction process, the

intermediate steps of distintegration of material and then the critical dehydration of such disintegrated raw garbage from about 35 per cent moisture to about 10 per cent moisture by indirect heat.

6. In a garbage reduction process, the steps of first removing 'free Water from the green garbage, then preliminary dehydration of the'green garbage by direct heat, then further dehydration by indirect heat, extraction of fats, and theredrying of the tankage by indirect heat.

7. The process of garbagereduction consisting Of first removing the free water, then dehydrating the green garbage in a direct heat dehydrator from per cent moisture to about 35 per cent moisture, sorting the partially dehydrated. garbage and disintegrating the sorted garbage, further dehydration through the critical zone from about 35 per cent moisture to about 10 per cent moisture in an indirect heat dehydrator, then extracting the fats from the dried garbage, and then redrying the resultant tankage from the extractor in. a second indirect heat dehydrator.

Signed by us, this ROBERT. D. MACLAURIN. CHARLES 0. SMITH.

27th day of February, 

